Broadband transmission characterization of indoor building materials using terahertz time-domain spectroscopy

The demands for achieving larger transmission capacity, lower latency, and higher efficiency are driving the carrier frequency to evolve up to the terahertz (THz) band. Understanding the optical and dielectric properties of indoor building materials within the THz frequencies is crucial for designing a reliable and robust propagation channel in the future wireless communication system. In this paper, four common indoor building materials, namely, ceramic, gypsum plasterboard, polymethyl methacrylate (PMMA), and soda-lime float glass, are systematically recorded using THz time-domain spectroscopy in the transmission configuration. The frequency-dependent refractive index n ( ν ), absorption coefficient α ( ν ), complex permittivity ε ( ν ), electrical conductivity σ ( ν ), as well as loss tangent tan δ ( ν ) are calculated based on Fresnel equations from 200 GHz to 3 THz. These measured material parameters can serve as a valuable database for modeling the propagation channel of future 6G communications.